burke



(No Model.) v 2 Sheets-Sheet 1. G. G. BURKE.

REGULATOR FOR ELECTRIC MOTORS.

Patented May 13, 18 84.

INVENTOR Charles GBur/se,

w k y B 2 Sheets-Sheet 2.

(No Model.)

10. G. BURKE.

REGULATOR FOR ELECTRIC MOTORS.

Patented May 13, 1884.

| NV EN TOR Charles QBur/re,

WITNESSES w QM By his Attorneys N. PUERS, Pholo-Liumgnphl walh'm mm D. C.

Unrrnn dramas Pater-tr airmen.

CHARLES G. BURKE, OF RICHMOND HILL, NEW YORK.

REGULATQR FOR ELECTEC EVEOTGRS.

SPECIFICATION forming part of Letters Patent No. 298,550, dated May 13, 1884:.

Application filed November 22, 1883. (No model.)

. citizen of the United States, residing at Richmond Hill, in the county of Queens and State of New York, have invented certain new and useful Improvements in Apparatus for Regulating and Controlling Electric Motors, of which the following is a specification.

My invention relates to certain improvements in the method of and apparatus for regulating the speed of electric motors.

The object of the invention is to provide means whereby the rate of revolution of the arniatures of electric motors of well-known construction may be regulated without modi-' fying the strength of the electric currents employed'for actuating the same.

The invention consists in applying to an electric motor which is actuated by electric impulses transmitted through each of a series of actuating electro-ma-gnets in succession a device which may be so adjusted as to modify the duration of the successive impulses thus transmitted. By this means the periods during which the successive electro-magnets exert an attractive force upon the armature are modified, and the consequent speed of the armature is regulated.

In the accompanying drawings, which illustrate my invention, Figure 1 is a plan view of the motor, partly in section, and Fig. 2 is a vertical section of the same. Fig. 8 is a detached view showing certain details of construction. Fig. 4.- illustrates a modification in the construction of the second circuit-closer, and Fig. 5 is a diagram illustrating an organization of circuits as applied to the invention.

Referring to the drawings, A represents the base upon which the various parts of the motor are supported, and B, B and 13 represent three electro-magnets having their poles projecting toward a common central axis, 0, of an armature, O. The poles of the electro-magnets terminate in a cylindrical case, b, of nonmagnetic material. A rotating armature, C, is supported within this case, and is constructed with four soft-iron extensions, 0, c c and c. The armature C is mounted upon a vertical axis, 0, which permits of the revolution of the armature in response to the attraction exerted by the several electro-magnets in succession.

The electromagnets are vitalized by means of an electric current which is transmitted to the electro-magnets in the proper succession by means of a circuit-controlling device, D, a plied to the shaft 0. The device I) consists of four contact-points, d, (2, (Z and d, which are designed to be successively placed in electrical connection with three contact rollers or brushes, 0, c and c". The contact-points d are all in electrical connection with one pole of an electric battery through the shaft 0 of the armature and a binding-screw, 1. The contact brushes or rollers e, e", and e are respectively placed in electrical connection with the outer terminals of the coils of the respective electromagnets B, B and B, the inner terminals of which coils are in electrical connection with each other through a metallic ring, 6, secured to but insulated from the base A of the instrument. The ring b is designed to be placed in electrical connection with the remaining pole of the battery by means of a conductor attached to a binding-post, 2. The function of the circuit-controller D is the same as that of the corresponding circuit-controller in any of the well-known forms of electric motors, the revolution of the armature serving to place 'one of the contact-points in electrical connection with the contact-roller which is connected with the coils of the next succeeding electro-magnet of the series, thereby causing thearmature to be advanced until it has reached the neutral point of that electro-magnet, whereupon the circuit -connections are completed by the action of the next succeeding circuit closer through the coils of the next electromagnet, and this succession of connections will be continued indefinitely by the revolution of the armature. It is evident, therefore, that the rapidity with which the armature will revolve when this circuit-controller alone is employed will be primarily dependent upon the inertia of the armature and the strength of the current of electricity, and that if these two elements are constant the rate of revolution will also be practically constant. If, however, it is desired to modify this rate more or less, it would be necessary to modify the strength of the battery or the current received therefrom, or to adjust the position of the circuit-closing rollers with refcontact-rollers c.

erence to their respective electro -1nagncts. The former method is, for obvious reasons, imperfect, and the latter method is undesirable, for the reason that it necessitates the adjustment of the coinimitator-brushes to such positions that the eil'ective force of the respective electro-magnets will be diminished by reason of the greater distance through which they are forced to act upon the armature, while the amount of current through which they are vitalized is not changed. Such a method of adj ustment would tliiere'lln'e necessitate a waste of electrical energy.

For the purpose olsecuring the required adjustment without involving such loss of energy, I apply to the shaft a second circuitclosing device,1l.. This device consists of four contact-points, 71,, 71?, if, and h", which are in electrical connection, through the shaft 0, with the four points (1, d, d, and d, and are preterably though not necessarily located in the same vertical lines. A single contact-brush, h, is represented in Fig. 3 for completing the connections of a battery through these points in succession during the revolution of the armature. The contactbrush h is placed in electrical connection with a binding-post, 3, and it is rendered adjustable in a manner hereinafter described. It will be seen, thus, that if one pole of the battery be connected with the ring I), and the remaining pole of that battery with the contact-brush h, the period during which the circuit of the battery will be completed through the corresponding contactroller will depend upon the position of the contact-brush h. with reference to one or the Thus if the contact-brush 72 be in the same vertical line with one of the contact-rollers, 0, it will remain in contact with one of the c ntact-points it, if, 72 or 71 during the time one of the contact-points d, d, d, or d is passing the contact-roller a, provided the extent of contact-surface of the two systems of contacts is equal. If, however, the contactdn-ush h be so adjusted as to extend in a vertical line slightly diil'ering from that of the eircuit-closing point, the time during which the circuit of the battery will be completed through both that point and the contact-brush 0' will be correspondingly shortened, and the duration of the periods in which the attraction is exerted by the corresponding elcctro-magnet upon the armature will be correspondingly shortened. The rate of the revolution of the armature will thereby be reduced.

I prefer io construct the contactpoints d 01 suillcient width to insure the completion oi the circuit-coin1ections at all times through some one of the contactu-ollers 0, thus avoiding any dead-points in the revolution of the armature.

For the purpose of readily adjusting the position of the brush it, I mount it upon a revolving carriage, K, which is provided with a milled head, it, by means of which it may be turned upon an axis concentric with the armaturc axis The adjustment may, however, be rendered more accurate by means of a worm, r, and screw-thread s, acting upon the head L" in the manner illustrated in Fig. i. A. graduated scale, t, Fig. at, is also preferably applied to the motor, and an index, at, attached to the moving carriage K, projects over this scale, by means of which the position of the contact-brush may be accurately determined.

It will be observed that, according to the construction illustrated in Figs. 2 and 3, the modilied currents can be transmitted through only the particular electro-magnet with which the contact-roller c is connected. 33y supplying an independent contaetbrush 7:, as shown at 72/, h, and it in Fig. i, for each contact-roller e, c", and 0, respectively, each elect-r0 magnet may be employed for actuating the armature in precisely the same manner as described with reference to the contact-brush h. This latter organization is preferable for most purposes. There are two methods whereby the adjustment may be cmployed-iirst, by supplying the entire current which is employed for actuating the motor through the brushes h, and, second, by applying a battery of sufficient force for overcoming the inertia of the armature directly to the contact-rollers 0 through the binding-posts 1 and 2 and supplying the controlling-current through the brushes h. The adjustment of the brushes it will in either case effect the required regulation of the movements of the armature. The latter method, which is of especial importance in cases where it is desired to employ a series of electric motors in a single electric circuit, and to cause each to rotate at the same speed, is illustrated in Fig. 5. M, M, and M represent a series of three ntors, each primarily actuated by electric cur rents from local batteries 0, o", and 0", respectively connected with the bindingposts l and 2 of each motor. The controlling-currents are supplied from a battery, 0, one of the poles of which is connected through the contact-brush 7t of the first or controlling motor with the succeedin g motor, and through the earth with the remaining pole of the battery. The strength of the current supplied by the battery 0 bears such relations to the currents from the batteries 0, o", and 0 that it controls the speed of the several motors, which will all be actuated at the same rate oi. speed.

It is evident that in this manner the circuitcontrolling device ill, applied to a single inotor, maybe employed for controlling the speed of the entire series, and this controlling-motor may be any one 01' the series. Thecontacts of the brushes h of the other meters of the series are preferably continuous.

I claim as my in.vention-- 1. The combination, substantially as here inbefore set forth, of a revolving armature, a series of electro-magnets, a cireuit-controlling In this figure device for transmitting electric currents to said I by electric currents may be transmitted from 20 electro-magnets in the proper succession to actuate said armature, and a second circuitcontrolling device for modifying the duration of the electric currents thus transmitted.

2. The combination, substantially as here-- inbefore set forth, with an electric motor, of an independent circuit controlling device, whereby the duration of the electric currents transmitted through the coils of said motor may be modified.

3. The combination, substantially as hereinbefore set forth, with a series of electro-magnets, an armature common to all of said magnets, a battery, and means, substantially such as described, for transmitting electric impulses from said battery through said electromagnets in succession, of a second battery and an adjustable circuit-controllin g device, Wherethe last-named battery through said electromagnets coincident with the first currents, but of less duration.

regulating the speed of electric motors, which consists in vitalizing the actuating electromagnets through the agency of electric currents of determinate duration, and simultaneously supplying controlling-currents of less duration.

In testimony whereof I have hereunto sub- CHARLES G. BURKE.

\Vitnesses:

DANIEL W. EDGECOMB, OHARLEs A. TERRY.

4E. The hereinbefore-described method of scribed my name this 1st day of November, 

